Dishwasher question

Hey all, had a question, was there a specific year when dishwashers were required to have a built in back-flow device installed, also, with that style dishwasher, does the waste discharge line still have to rise up and fasten to the underside of counter, have been seeing some new installations where the discharge line is almost direct (no loop or fastening to underside of cabinet) thanks, PS, fairly New Construction.

They are required to have an air gap.

Recommend an air gap or high loop to prevent bacterial infection.Only a air gap is acceptable by code however.

Thanks bob for confirming the loop, still stuck on the air gap thing, I do not always see those on newer installs, I assumed it was because the newer ones were equipped with an integral back flow device, with no need for air gap.

You would have no way of knowing that.Assume none do.

Thanks Bob, I will just write up, no visible Air Gap, Discharge line should have loop. are most HI`s running full cycle of dishwasher, thanks.

You are not required to check appliances in the SOP but to answer ,yes I do.

Thanks bob.

2009 IRC P2717.2 Sink and dishwasher.A sink and dishwasher are permitted
to discharge through a single 11/2-inch (38 mm) trap.
The discharge pipe from the dishwasher shall be increased to a
minimum of 3/4 inch (19 mm) in diameter and shall be connected
with a wye fitting to the sink tailpiece. The dishwasher
waste line shall rise and be securely fastened to the underside of
the counter before connecting to the sink tailpiece.

**Commentary: **Dishwashing machines may connect directly to the
drainage system and do not require an indirect connection
by drainage air gap or air break
. The direct
connection is acceptable, because the potable water
supply is adequately protected against backflow. This
section requires that the waste line be looped as high
as possible and be securely fastened to the underside
of the sink rim or countertop to minimize the potential
of waste backflow into the dishwasher unit (see Commentary
Figure P2717.2).

Does that include when connected ted to a disposal?(did not think so):slight_smile:
They are required here.


Section 890.770 Dishwashing Machines

a) Domestic Dishwasher (Private Residence). When a domestic dishwashing machine drain line is connected to the house side of a trap from a sink, the drain from the dishwasher shall be carried up to the underside of the spill rim of the sink. Dishwashing machines shall discharge separately into a trap or tail piece of the kitchen sink and** shall not connect to the food waste disposal unit. **

But allowed in other states Chris.
Airgaps are required in Chicago.

This makes for a good general statement.

Airgaps are now standard equipment to assure a separation between
supply and waste water. It is advised that either an airgap or a high loop
be installed between the dishwasher and the waste connection

I know. Chicago’s in IL. :smiley:

You said “Does that include when connected to a disposal?”

That also is not allowed in Chicago, or the other half of Illinois.

How about the poster of the thread?
Is Canada part of Illinois.:slight_smile:

If he is in Canada then why did you post “Only a air gap is acceptable by code however.” ? Are you that familiar with Canadian codes? :wink:

That is a side bar with Chris.He does well on his own, big brother.

CA still requires an air-gap. The state code is crystal clear on this issue, although there are some incorporated municipalities that allow a direct connection.